RPST
208.67.222.222 OpenDNS primary
208.67.220.220 OpenDNS secondary

8.26.56.26 Comodo Secure DNS primary
8.20.247.20 Comodo Secure DNS secondary

9.9.9.9 Quad9 primary
149.112.112.112 Quad9 secondary

64.6.64.6 Verisign DNS primary
64.6.65.6 Verisign DNS secondary